Burglar-proof key-clamp.



D. W. SHAFPER. BURGLAR PROOF KEY CLAMP. APPLIOATION FILED AUG. 12, 1912.

051.67 5- Patented Apr. 1, 1913.

DANIEL W. SHAFFER, 0F CHATTANOOG-A, OKLAHOMA.

BURGLAR-PROOF KEY-CLAMP.

Specification of Letters Patent.

Patented Apr. 1,1913.

Application filed August 12, 1912. Serial No. 714,657.

To all whom it may concern:

Be it known that I, DANIEL W. SHAFFER, a citizen of the United States, residing at Chattanooga, in the county of Comanche and State of Oklahoma, have invented a new and useful Improvement in Burglar- Proof Key-Clamps, of which the following is a specification.

The invention relates to key clamps and has for its object the provision of a simple, inexpensive, yet eiiicient means for preventing removal of a door-key from its lock.

The merits, construction and scope of the invention will be readily understood from the following description and appended claim, when construed in connection with the accompanying drawings, forming part of this specification, in which,-

Figure 1 is a perspective View of a device designed in accordance with my invention; Fig. 2 is a fragmentary front elevation of a door-stile, showing the clamp adjusted to the door key; and Fig. 3 is a fragmentary side elevation of the same.

In the illustrations, like letters of reference designate corresponding parts throughout the several views.

The device is preferably constructed of a light weight material and in the form clearly illustrated in Fig. 1, which comprises a cylindrical, hollow body A, the lower portion of which is bifurcated, forming jaws B and C, which are internally-toothed and adjustable toward and from each other by means of a thumb-screw D passed through said jaws and threaded into the jaw B. It will thus be seen that screwing the thumbscrew will draw the jaws inwardly toward each other, while unscrewing said screw will permit their retraction due to spring tension of the jaws.

The body A is preferably of a size to accommodate an ordinary lead pencil, thus affording a convenient means of carrying and also applying the device, as will presently be .clearly set forth.

Figs. 2. and 3 clearly show the device clamped to the key G in the key hole h of the stile H.

In applying the device the stile is locked; the key being turned in the locking direction as far as possible, so that it is in a position oblique to the key-way; the clamp' is then attached to the key and, as described and illustrated, a pencil, or similarly shaped instrument, inserted in the body of the clamp bears against the stem f of the door-knob F, thus preventing unturning and removal of the key by a person on the opposite side of the stile from which the device is attached.

Having thus described my invention,what I claim as new and desire to secure by United States Letters Patent, is,

A device of the class described, comprising a hollow cylindrical body, two spring jaws, internally-toothed and integral w1th the body portion, and a thumb-screw for the adjustment of said jaws, substantially as set forth.

Signed by me this 8th day of August,

1912, in the presence of two witnesses.

DANIEL WV. SHAFFER. Witnesses:

HUGH MOSSMAN, R. A. WOLTERSDORF.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. Y 

